Improvement in heating and ventilating cars



UNITED. TATES PATENT FFICE.

WILLIAM E. PRALL, OF NEW YORK/N. Y., ASSIGNOR T() J. L. PRALL, OF SAME PLAGE.

IMPROVEMENT IN HEATING AND VENTILATING CARS.

Specification forming part of Letters Patent No. 218,685, dated August 19, 1879; application filed May 16, 1879.

l. noyance of stoves or fire located on the cars. :"To accomplish this end I propose to establish at the terminal station a large heating-tank, A, constructed as an ordinary steam-boiler, but to be used for heating liquid substances possessing a very high capacity for receiving fr and retai11ingheat,such as oils. Among those best adapted for the purpose are hnseed-oil and lard,A the former requiring six hundred and forty degrees (6400) of heat before the boiling-point is reached.

The manifold advantages of employing such a (medium will be readily comprehended. First, the quantity or bulk and weight to be carried will be small; and, secondly, the intensity of the heat and the capacity of the QL substance for retaining it will be very great.

There will be further advantages in employing such media in that they will not solidify when exposed to frost-at least the linseed-oil will not, nor will it permeate the iron tanks in which it is proposed to carry it on the cars.

In the illustration, `K represents a steamboiler; B, a force-pump 5 C, a pipe or hose extending from the pump to one end of the receiving-tank E, placed under A,the seat of the car M; C', a pipe extendinglfrom the heatingtank A to the pump B. `D is another pipe, extending from the heating-tank directly to the opposite end of the receiving-tank E. c and cl represent a coupling arrangement for uniting the pipes C and D with the branch pipes l? I at each end of the tank E. L andL and S and S represent cocks or plugs placed in the branch pipes P and P and in the supply and exhaustpipes C and D, the object of these cocks being to enable the operator to shut oft' communication between the heating-tank and the receiving-tank before dis mnnectng thecouplings c and d. H represents a register foradmitting cold air into the chamber containing the tank E and F represents the registers controlling the admission of hot-air from the chamber into the interior of the car. a represents a piston moving on the rod b within the receiving-tank E.

In the practical operation of my system the cars are run into the station in which theheating-tank is placed, and the operator immediately unites the supply and exhaust pipes G and D with the opposite ends of the tank E by means of the adjustable couplings. The cocks controlling the communication are then opened, and by means of the force-pump the oil is forced through the pipe (l directly from the heating-tank into the receiving-tank on the car. The piston in said tank will divide the hot oil from that which has been cooled by radiation during the last trip over the road 5 and as the fresh supply is forced into said tank the piston will be forced in the opposite direction, and that contained in the tank will be driven out and conveyed by means of the exhaust-pipe D back into the heating-tank A.

As soon as the complete exchange has been made the cocks will be closed and the pipes C and D disconnected, and the car is ready for another trip.

The connection of the supply and exhaust pipes C and D with the oil-tank must be reversed each time it is filled, in order that the piston may be driven in opposite `directions at each filling of the same.

It will be seen that the piston acts only as a movable partition between the outflowing and inliowing oil, and moves freely with the same.

By this simple arrangement all of the cars may be 4warmed from one large fire and under the control of one operator, thereby saving much time and expense in fuel and labor that would be required if stoves and separate lires were used in each car, and also a much more desirable and uniform temperature may be preserved and much better ventilation obtained.

The great heat contained in the oil Will be suicient for warming the car for the length of time required for the trip. There can be no possible danger from overpressure in the tanks, as it will not be necessary to have the oil heated beyond the boiling-point, and at that temperature the pressure is only equal to that ofthe atmosphere; hence there is really no pressure exerted on the tank containingit.

The same oil can be used over and over for an indeinite time, and there will be no expense except for the first purchase, which would not be large.

The tank can be very small, and if it should be necessary to increase the radiating-surface it may be done by placing corrugated sheetiron over its outer surface.

There may he a tank placed on each side of the car, if necessary.

As there are many kinds of oil and other substances which have a great capacity for receiving and retaining heat, I do not confine myself to any one, nor to any particular position on the car for placing the receivingtanks; but they should be placed under the seats, Where they will be entirely out of the way.

It is also evident that many dierent kinds of pump might be employed for exchanging the oil from the heating-rank to the receivingtank on the car; or it might be done by forcing the oil from the heating-tank into the receiving-tank, and from the receiving tank into another tank placed above the heating-tank, by having a greater pressure in one than in the other by the admission of steam or air, and then it could be returned to the heatingtank by its own gravity by turning the cock placed in the pipe connecting the two, thus doing away with the pump for that purpose.

The receiving-tanks may be easily removed during the summer months, when no heatis required.

I am aware that oils, on account of the great specific heat obtained without pressure by them, have been used for superheating steam and for drying purposes; hence I do not claim, broadly, the use of them for heating purposes generally.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In an apparatus for heating and ventilating street-cars, a tank carried with the car, and provided with inlet and exhaust pipe connections, and with a movable piston, serving as a partition between the supply and discharge oil to prevent their commingling, substantially as and for the purpose set forth.

2. In an apparatus for heating and Ventilating street-cars, the stationary oil-heating tank and the portable heat-radiating tank, charged with linseed or other oil, carried on or with the car, said tanks being provided with adjustable connecting-pipes, and with the necessary cocks for opening and closing the same, in combination with a forcing apparatus for conveying the oil alternately from the heating-tank to the radiating-tank, and from the radiating-tank back to the heating-tank, constructed and operating together for the purpose set forth.

W. E. PRALL.

Witnesses:

STEvENsoN TowLE, Gao. HACKETT. 

